Why I can't kill these threads by using "join"?

I am learning concurrency with C++ 11 currently. I got stuck on a coursework. I wrote a piece of code. The join() function is meant to kill all the threads after their running. However, it doesn't. And, the join() function never ends in my code.

What I have tried: Adding printing words around the join();. I think the output shows that the join(); doesn't finish running.

My environment:

System: Windows 10

Compiler: mingw-w64x86_64-8.1.0-posix-seh-rt_v6-rev0

Code:

#include <iostream>
#include <thread>
#include <mutex>          // std::mutex, std::unique_lock
#include <condition_variable> // std::condition_variable

using namespace std;

std::mutex mu; //mutex
//std::unique_lock<mutex> locker(mu); //unique_lock
std::condition_variable cond;

std::mutex m_mutex;

class Buffer {
public:
Buffer():count(0) {}
void put();
int get();
bool isBufferEmpty();
bool isBufferFull();
private:
int count;
}; //end class Buffer

//Thread Class and Functions inside:
class Consumer{
public:
    Consumer(Buffer* cbptr);
    void cons();
    bool isConsumerDead();
private:
    Buffer* BufferPtr;
    int consumerDeadFlag;
};

class Producer{
public:
    Producer(Buffer* pbptr, Consumer* coptr);
    void prods();
private:
    Buffer* BufferPtr;
    Consumer* ConsumerPtr;
};

int main(){
    Buffer* tc = new Buffer();
    Consumer* cdtc = new Consumer(tc);
    Producer* pdtc = new Producer(tc,cdtc);
    std::thread t[5]; //declare an array of thread objects
    int i = 0;
    for(; i<3; ++i){
        t[i]=std::thread(&Producer::prods,std::ref(pdtc));
    }
    for(; i<5; ++i){
        t[i]=std::thread(&Consumer::cons,std::ref(cdtc));
    }

    cout << "Debug1" << endl;
    cout << "Debug1" << endl;
    cout << "Debug1" << endl;

    for(i = 0; i<5; ++i){
        t[i].join();
        cout << "now i is :" << i << endl;
    }

    cout << "All threads terminated" << endl;
    return 0;
}

void Buffer::put(){
    std::unique_lock<mutex> locker(mu); //unique_lock
    while(isBufferFull()==1){
        cond.wait(locker);
    }
    if(isBufferFull()==0)
        cond.notify_one();
    ++count;
    std::cout << "producer thread" << this_thread::get_id() << ",count = " << count << endl;
}
int Buffer::get(){
    std::unique_lock<mutex> locker(mu); //unique_lock
    while(isBufferEmpty()==1){
        cond.wait(locker);
    }
    if(isBufferEmpty()==0)
        cond.notify_one();
    --count;
    std::cout << "consumer thread" << this_thread::get_id() << ",count = " << count << endl;
    return count;
}
bool Buffer::isBufferEmpty(){
    if(count <=0){
        std::cout << "buffer is empty, consumer thread" << this_thread::get_id() << " is about to suspend." << endl;
        return 1;
    }
    else
        return 0;
}
bool Buffer::isBufferFull(){
    if(count >=10){
        std::cout << "buffer is full, producer thread" << this_thread::get_id() << " is about to suspend." << endl;
        return 1;
    }
    else
        return 0;
}

Consumer::Consumer(Buffer* cbptr):BufferPtr(cbptr){
    consumerDeadFlag = 0;
}

bool Consumer::isConsumerDead(){
    if(consumerDeadFlag > 1){
        cout << "consumer Dead" << endl;
        cout << "consumer Dead" << endl;
        cout << "consumer Dead" << endl;
        return 1;
    }
    else
        return 0;
}

void Consumer::cons(){
    for(int i = 0; i<100; ++i){
        BufferPtr->get();
        std::this_thread::sleep_for(std::chrono::milliseconds(10));
    }
    ++consumerDeadFlag;
}

Producer::Producer(Buffer* pbptr, Consumer* coptr):BufferPtr(pbptr), ConsumerPtr(coptr){}

void Producer::prods(){
    for(int i = 0; i<100; ++i){
        if(ConsumerPtr->isConsumerDead()){
            break;
        }
        BufferPtr->put();
        std::this_thread::sleep_for(std::chrono::milliseconds(10));
    }
}

Output:

producer threadDebug12,count = 1
producer thread4,count = 2

producer thread3,count = 3
Debug1
Debug1
consumer thread5,count = 2
consumer thread6,count = 1
producer thread2,count = 2
consumer thread5,count = 1
producer thread4,count = 2
producer thread3,count = 3
consumer thread6,count = 2
producer thread2,count = 3
producer thread4,count = 4
producer thread3,count = 5
consumer thread5,count = 4
consumer thread6,count = 3
producer thread2,count = 4
producer thread4,count = 5
consumer thread5,count = 4
producer thread3,count = 5
consumer thread6,count = 4
producer thread2,count = 5
consumer thread5,count = 4
producer thread4,count = 5
producer thread3,count = 6
consumer thread6,count = 5
producer thread2,count = 6
producer thread4,count = 7
producer thread3,count = 8
consumer thread5,count = 7
consumer thread6,count = 6
producer thread2,count = 7
consumer thread5,count = 6
producer thread4,count = 7
producer thread3,count = 8
consumer thread6,count = 7
producer thread2,count = 8
consumer thread5,count = 7
producer thread4,count = 8
producer thread3,count = 9
consumer thread6,count = 8
producer thread2,count = 9
producer thread4,count = 10
consumer thread5,count = 9
producer thread3,count = 10
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
buffer is full, producer thread4 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread4 is about to suspend.
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
buffer is full, producer thread4 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
buffer is full, producer thread4 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread4 is about to suspend.
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
buffer is full, producer thread4 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
buffer is full, producer thread4 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread4 is about to suspend.
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread4 is about to suspend.
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread3 is about to suspend.
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
buffer is full, producer thread4 is about to suspend.
consumer thread5,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
buffer is full, producer thread2 is about to suspend.
consumer thread6,count = 9
producer thread4,count = 10
buffer is full, producer thread2 is about to suspend.
consumer thread5,count = 9
producer thread2,count = 10
buffer is full, producer thread3 is about to suspend.
consumer thread6,count = 9
producer thread3,count = 10
buffer is full, producer thread4 is about to suspend.
buffer is full, producer thread2 is about to suspend.

etc. (due to the limit of words)

consumer Dead
consumer Dead
consumer Dead